聚甲基乙撑碳酸酯/氧化石墨烯纳米复合材料的制备及性能研究

Preparation of poly(propylene carbonate)/poly(vinyl alcohol)/graphene oxide nanocomposite and its properties

本文采用改进Hummers法制备氧化石墨烯(GO),通过原子力显微镜对GO片层形貌进行表征;以聚甲基乙撑碳酸酯(PPC)、聚乙烯醇(PVA)和氧化石墨烯(GO)为原料,采用溶液和熔融共混法相结合,制备PPC/PVA/GO纳米复合材料,研究其力学性能、热学性能和动态流变行为。结果表明,当GO含量为0.5 wt%时,拉伸强度达到了22.03 MPa,与纯PPC相比提高了25.8%;当GO含量增大到1.0 wt%时,拉伸强度开始降低;断裂伸长率随GO的加入呈现降低的趋势。GO含量为1.0%时复合材料的热学性能最好,与纯PPC相比,复合材料的完全热分解温度从350℃提高到了400℃以上,并且热分解速率下降了12%/min;复合材料的复数黏度、储能模量和损耗模量随PVA及GO的引入也有一定程度的提高。

Poly( propylene carbonate)( PPC) is a biodegradable and biocompatible polymer with excellent properties obtained by polymerization of propylene oxide( PO) and carbon dioxide( CO_2). However,its poor thermal stability and mechanical strength limit the practical application of PPC.In this work,Graphene oxide( GO) was prepared by the improved Hummers method.The morphology of GO was characterized by AFM.Solution blending and melt blending was used to make GO well-dispersed in the Poly( propylene carbonate)( PPC) matrix to improve thermal stability and mechanical strength.The poly( vinyl alcohol)( PVA) acted as a dispersion medium.Owing to a large number of oxygen-containing groups on the surface of GO nanosheets,hydrogen bonding between GO and PPC was supposed,which facilitated to the improvement of thermal stability and mechanical strength of PPC/PVA/GO nanocomposites.Effect of GO content on the properties of PPC/PVA/GO composites was analyzed.The obtained PPC/PVA/GO nanocomposites displayed an improved mechanical properties by adding 10 wt%PVA and a small amount of GO.The results showed that the tensile strength improved 25. 8%at most compared with the pure PPC.The decomposition temperature and the glass transition of the samples are enhanced.The complex viscosity,storage modulus and loss modulus of PPC/PVA/GO composites is obviously higher than that of pure PPC.